The apparatus herein relates to an oscillating piston and cylinder construction which may be used as a pump, such as is described in my U.S. Pat. No. 3,489,335, now reissued as U.S. Pat. No. Re. 27,740 or as a gas analyzer mechanism such as is disclosed in my U.S. Pat. No. 3,516,745, or as part of an engine such as is described in U.S. Pat. No. 3,583,155, or other devices which utilize thermal energy for power. The apparatus herein is a simplification of and in some directions an improvement of the equipment described in the foregoing patents and applications.
More specifically, the present invention provides .[.more.]. .Iadd.some .Iaddend.preferred forms of heat transfer surfaces for driving a moving part, e.g., a piston, whereby the heat transfer surfaces are in structures that are relatively efficient and compact. Means are also provided for eliminating some or all of the valves and other pieces of mechanism which were utilized in the abovementioned equipment for restricting fluid flow into a heating chamber and for positioning the center .[.or.]. .Iadd.of .Iaddend.piston oscillation.